[Dr_C]

The wireless version of the 12/24/36 car system is starting to take shape.

For me the starting point is a frequency hopping algorithm.

The idea of frequency hopping is to avoid signal fade which happens across the 2.4GHz frequency band when the direct line-of-sight signals interfere with reflected signals (for example off nearby walls) leading to poor signal strength. Fortunately these weak spots occur in different physical locations for different frequencies. Hence, frequency hopping solves the problem of signal fade. It has become standard practice in 2.4GHz radio control systems over recent years for example the DSM-X system from Spektrum.

My system approach starts with frequency hopping and adds in 8bit throttle/brake signals with an overall system refresh rate of 100Hz. Each car decoder will receive two signals on different frequencies every 10msec. In addition both of these frequencies hop every 10msec.

And if a decoder happens to power down as it crosses a lane changer, the decoder re-locks onto the first 10msec control frame that it receives i.e. no re-synchronisation delays.

As I say, progress so far is good. I have transmitter and receiver modules running with the above mentioned frequency hopping plus 8bit throttle/brake data which refreshes at 100Hz. 

The terms transmitter and receiver are a bit of a simplification here as both devices do both. Control data flows in both directions every 10msec.

Next I need to embed these algorithms into throttle controller hardware  and in-car decoder hardware.

The hardware to take this to the next level of demonstration (i.e. cars being driven on track) has been built up over recent months. This hardware is ready for the new code :)

c